Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| influence of viral genes on the cell-to-cell spread of rna silencing. | the turnip crinkle virus-based vector tcv-gfp delta cp had been devised previously to study cell-to-cell and long-distance spread of virus-induced rna silencing. tcv-gfp delta cp, which had been constructed by replacing the coat protein (cp) gene with a green fluorescent protein (gfp) coding sequence, was able to induce rna silencing in single epidermal cells, from which rna silencing spread from cell-to-cell. using this unique local silencing assay together with mutagenesis analysis, two tcv ge ... | 2008 | 18515824 |
| agrobacterium tumefaciens-induced bacteraemia does not lead to reporter gene expression in mouse organs. | agrobacterium tumefaciens is the main plant biotechnology gene transfer tool with host range which can be extended to non-plant eukaryotic organisms under laboratory conditions. known medical cases of agrobacterium species isolation from bloodstream infections necessitate the assessment of biosafety-related risks of a. tumefaciens encounters with mammalian organisms. here, we studied the survival of a. tumefaciens in bloodstream of mice injected with bacterial cultures. bacterial titers of 10(8) ... | 2008 | 18523638 |
| a versatile assay for the identification of rna silencing suppressors based on complementation of viral movement. | the cell-to-cell movement of turnip crinkle virus (tcv) in nicotiana benthamiana requires the presence of its coat protein (cp), a known suppressor of rna silencing. rna transcripts of a tcv construct containing a reporter gene (green fluorescent protein) (tcv-sgfp) in place of the cp open reading frame generated foci of three to five cells. tcv cp delivered in trans by agrobacterium tumefaciens infiltration potentiated movement of tcv-sgfp and increased foci diameter, on average, by a factor of ... | 2008 | 18533829 |
| coat protein-mediated resistance against an indian isolate of the cucumber mosaic virus subgroup ib in nicotiana benthamiana. | coat protein (cp) -mediated resistance against an indian isolate of the cucumber mosaic virus (cmv) subgroup ib was demonstrated in transgenic lines of nicotiana benthamiana through agrobacterium tumefaciens-mediated transformation. out of the fourteen independently transformed lines developed, two lines were tested for resistance against cmv by challenge inoculations. the transgenic lines exhibiting complete resistance remained symptomless throughout life and showed reduced or no virus accumula ... | 2008 | 18535359 |
| in vitro replication of bamboo mosaic virus satellite rna. | an in vitro system was applied to analyze the replication of a satellite rna of bamboo mosaic virus (bamv), designated satbamv rna, using solubilized membrane-bound rna-dependent rna polymerase (rdrp) complexes isolated from bamv-infected nicotiana benthamiana. after removal of endogenous templates, the rdrp complexes of bamv catalyzed rna synthesis upon the addition of the full-length positive (+)- or negative (-)-strand satbamv rna transcripts used as templates. both (+)- and (-)-satbamv rna p ... | 2008 | 18538884 |
| inhibition of 3' modification of small rnas in virus-infected plants require spatial and temporal co-expression of small rnas and viral silencing-suppressor proteins. | plant viruses are inducers and targets of rna silencing. viruses counteract with rna silencing by expressing silencing-suppressor proteins. many of the identified proteins bind sirnas, which prevents assembly of silencing effector complexes, and also interfere with their 3' methylation, which protects them against degradation. here, we investigated the 3' modification of silencing-related small rnas in nicotiana benthamiana plants infected with viruses expressing rna silencing suppressors, the p ... | 2008 | 18539609 |
| transreplication of a tomato yellow leaf curl thailand virus dna-b and replication of a dnabeta component by tomato leaf curl vietnam virus and tomato yellow leaf curl vietnam virus. | the genomes of two tomato-infecting begomoviruses from vietnam were cloned and sequenced. a new variant of tomato leaf curl vietnam virus (tolcvv) consisting of a dna-a component and associated with a dnabeta molecule as well as an additional begomovirus tentatively named tomato yellow leaf curl vietnam virus (tylcvv) consisting also of a dna-a component were identified. to verify if monopartite viruses occurring in vietnam and thailand are able to transreplicate the dna-b component of tomato ye ... | 2008 | 18550192 |
| the 5' untranslated region of the maize alcohol dehydrogenase gene contains an internal ribosome entry site. | adh1, the maize gene encoding alcohol dehydrogenase adh1, mrna is efficiently translated in o2-deprived roots of maize, whereas many normal cellular mrnas are poorly translated. it has been shown that adh, the 5' untranslated region of adh1 mrna, provides effective translation of mrna under hypoxia and heat shock conditions in nicotiana benthamiana plants. we found that adh contains the internal ribosome entry site (ires) active both in vivo, in n. benthamiana cells, and in vitro, in rabbit reti ... | 2008 | 18556149 |
| functional characterization and subcellular localization of the 16k cysteine-rich suppressor of gene silencing protein of tobacco rattle virus. | the 16 kda cysteine-rich protein (16k) of tobacco rattle virus (trv) is known to partially suppress rna silencing in drosophila cells. in this study, we show that 16k suppresses rna silencing in green fluorescent protein (gfp)-transgenic nicotiana benthamiana plants using an agrobacterium-mediated transient assay. 16k slightly reduced the accumulation of short interfering rnas (sirna) of gfp, suggesting that the protein may interfere with the initiation and/or maintenance of rna silencing. delet ... | 2008 | 18559946 |
| diversity of begomoviruses associated with mosaic disease of cultivated cassava (manihot esculenta crantz) and its wild relative (manihot glaziovii mull. arg.) in uganda. | cassava (manihot esculenta) growing in uganda during 2001-2002 has been screened for the presence of begomoviruses using pcr-rflp, cloning full-length genomic components and nucleotide sequence analysis. in contrast with a recent survey in neighbouring kenya, which identified three distinct strains of east african cassava mosaic virus (eacmv, eacmv-ug and eacmv-ke2) as well as east african cassava mosaic zanzibar virus and the new species east african cassava mosaic kenya virus, only eacmv-ug an ... | 2008 | 18559947 |
| mutations that alter a repeated acca element located at the 5' end of the potato virus x genome affect rna accumulation. | the repeated acca or ac-rich sequence and structural (sl1) elements in the 5' non-translated region (ntr) of the potato virus x (pvx) rna play vital roles in the pvx life cycle by controlling translation, rna replication, movement, and assembly. it has already been shown that the repeated acca or ac-rich sequence affect both grna and sgrna accumulation, while not affecting minus-strand rna accumulation, and are also required for host protein binding. the functional significance of the repeated a ... | 2008 | 18589472 |
| viroid-induced symptoms in nicotiana benthamiana plants are dependent on rdr6 activity. | viroids are small self-replicating rnas that infect plants. how these noncoding pathogenic rnas interact with hosts to induce disease symptoms is a long-standing unanswered question. recent experimental data have led to the suggestive proposal of a pathogenic model based on the rna silencing mechanism. however, evidence of a direct relation between key components of the rna silencing pathway and symptom expression in infected plants remains elusive. to address this issue, we used a symptomatic t ... | 2008 | 18599649 |
| a novel type of thioredoxin dedicated to symbiosis in legumes. | thioredoxins (trxs) constitute a family of small proteins in plants. this family has been extensively characterized in arabidopsis (arabidopsis thaliana), which contains six different trx types: f, m, x, and y in chloroplasts, o in mitochondria, and h mainly in cytosol. a detailed study of this family in the model legume medicago truncatula, realized here, has established the existence of two isoforms that do not belong to any of the types previously described. as no possible orthologs were furt ... | 2008 | 18614707 |
| disassembly of african cassava mosaic virus. | the plant-infecting geminiviruses encapsidate their single-stranded dna genome in characteristic twinned particles that are unique among viruses. these particles are formed by joining two incomplete t=1 icosahedra. african cassava mosaic virions were purified by density-gradient centrifugation from infected nicotiana benthamiana plants and analysed for their stability with respect to ph changes and heat treatment by using electron microscopy. negative staining and rotary shadowing revealed stabl ... | 2008 | 18632975 |
| hc-pro protein of sugar cane mosaic virus interacts specifically with maize ferredoxin-5 in vitro and in planta. | symptom development of a plant viral disease is a result of molecular interactions between the virus and its host plant; thus, the elucidation of specific interactions is a prerequisite to reveal the mechanism of viral pathogenesis. here, we show that the chloroplast precursor of ferredoxin-5 (fd v) from maize (zea mays) interacts with the multifunctional hc-pro protein of sugar cane mosaic virus (scmv) in yeast, nicotiana benthamiana cells and maize protoplasts. our results demonstrate that the ... | 2008 | 18632977 |
| peanut stunt virus 2b cistron plays a role in viral local and systemic accumulation and virulence in nicotiana benthamiana. | to analyze the role of the 2b protein (2bp) of peanut stunt virus (psv) in the viral infection cycle, we constructed psv mutants that express either no 2bp or n-terminal-truncated 2bp. the accumulation of wild-type and mutant viruses in tobacco protoplasts indicated that the 2b cistron is not essential for viral replication. viral accumulation in nicotiana benthamiana plants suggested that the 2b cistron is responsible for viral accumulation in inoculated and upper leaves and has a role in virul ... | 2008 | 18663407 |
| effector genomics accelerates discovery and functional profiling of potato disease resistance and phytophthora infestans avirulence genes. | potato is the world's fourth largest food crop yet it continues to endure late blight, a devastating disease caused by the irish famine pathogen phytophthora infestans. breeding broad-spectrum disease resistance (r) genes into potato (solanum tuberosum) is the best strategy for genetically managing late blight but current approaches are slow and inefficient. we used a repertoire of effector genes predicted computationally from the p. infestans genome to accelerate the identification, functional ... | 2008 | 18682852 |
| nblrk1, a lectin-like receptor kinase protein of nicotiana benthamiana, interacts with phytophthora infestans inf1 elicitin and mediates inf1-induced cell death. | phytophthora infestans inf1 elicitin causes the hypersensitive response (hr) in nicotiana benthamiana (kamoun et al. in plant cell 10:1413-1425, 1998). to identify n. benthamiana proteins that interact with inf1, we carried out a yeast two-hybrid screen. this screen resulted in the isolation of a gene nblrk1 coding for a novel lectin-like receptor kinase. nblrk1 interacted with inf1 through its vib kinase subdomain. purified inf1 and nblrk1 proteins also interacted in vitro. inf1 treatment of n. ... | 2008 | 18682978 |
| characterization of resistance mechanism in transgenic nicotiana benthamiana containing turnip crinkle virus coat protein. | two transgenic lines, of nicotiana benthamiana expressing turnip crinkle virus (tcv)-coat protein (cp) gene with contrasting phenotype, the highest (#3) and the lowest (#18) cp expressers, were selected and challenged with the homologous tcv. the former, the highest expresser, showed nearly five times more cp expression than the latter. progenies of #3 and #18 lines showed 30 and 100% infection rates, respectively. the infected progenies of #3 line showed mild and delayed symptom with tcv. this ... | 2008 | 18704429 |
| role of a xyloglucan-specific endo-beta-1,4-glucanase inhibitor in the interactions of nicotiana benthamiana with colletotrichum destructivum, c. orbiculare or pseudomonas syringae pv. tabaci. | a xyloglucan-specific endo-beta-1,4-glucanase inhibitor cdna, nbxegip1, was amplified from diseased leaves of nicotiana benthamiana. the sequence was similar to the tomato xyloglucan-specific endo-beta-1,4-glucanase inhibitor (xegip) and tobacco nectarin iv genes that have been described as binding and inactivating fungal family 12 xyloglucan-specific endo-beta-1,4-glucanases. expression of nbxegip1 was not detected in healthy leaves, but the gene was induced during the later stages of infection ... | 2008 | 18705851 |
| high-throughput in planta expression screening identifies an adp-ribosylation factor (arf1) involved in non-host resistance and r gene-mediated resistance. | to identify positive regulators of cell death in plants, we performed a high-throughput screening, employing potato virus x-based overexpression in planta of a cdna library derived from paraquat-treated nicotiana benthamiana leaves. the screening of 30,000 cdna clones enabled the identification of an adp-ribosylation factor 1 (arf1) that induces cell death when overexpressed in n. benthamiana. overexpression of the guanosine diphosphate (gdp)-locked mutant of arf1 did not trigger cell death, sug ... | 2008 | 18705881 |
| hibiscus chlorotic ringspot virus coat protein inhibits trans-acting small interfering rna biogenesis in arabidopsis. | many plant and animal viruses have evolved suppressor proteins to block host rna silencing at various stages of the rna silencing pathways. hibiscus chlorotic ringspot virus (hcrsv) coat protein (cp) is capable of suppressing the transiently expressed sense-rna-induced post-transcriptional gene silencing (ptgs) in nicotiana benthamiana. here, constitutively expressed hcrsv cp from transgenic arabidopsis was found to be able to rescue expression of the silenced gus transgene. the hcrsv cp-transge ... | 2008 | 18753245 |
| bah1/nla, a ring-type ubiquitin e3 ligase, regulates the accumulation of salicylic acid and immune responses to pseudomonas syringae dc3000. | salicylic acid (sa) is a primary factor responsible for exerting diverse immune responses in plants and is synthesized in response to attack by a wide range of pathogens. the arabidopsis (arabidopsis thaliana) sid2 mutant is defective in a sa biosynthetic pathway involving isochorismate synthase1 (ics1) and consequently contains reduced levels of sa. however, the sid2 mutant as well as ics-suppressed tobacco (nicotiana benthamiana) still accumulate a small but significant level of sa. these obse ... | 2008 | 18753285 |
| ntbzip60, an endoplasmic reticulum-localized transcription factor, plays a role in the defense response against bacterial pathogens in nicotiana tabacum. | a spermine-based signal transduction pathway plays a defensive role against incompatible pathogens. we identified a novel spermine-responsive cdna from nicotiana tabacum that encodes a basic region/leucine zipper protein with a putative transmembrane domain. identity to arabidopsis thaliana atbzip60 was sufficiently high to name the novel cdna ntbzip60. expression analysis revealed that ntbzip60 is a component of the spermine-signal pathway, and is also involved in the unfolded protein response ... | 2008 | 18758894 |
| transfecting protoplasts by electroporation to study viroid replication. | protoplasts have been extensively used to study replication of plant viruses at the cellular level. however, their use in studying viroid replication has been very limited because of various technical barriers. as a result, mechanisms of viroid replication remain poorly understood. the electroporation protocol presented in this unit offers a simple, fast and reproducible method to inoculate protoplasts derived from cultured cells of tobacco (nicotiana tabacum) and the related species nicotiana b ... | 2005 | 18770558 |
| srfr1, a suppressor of effector-triggered immunity, encodes a conserved tetratricopeptide repeat protein with similarity to transcriptional repressors. | effector-triggered immunity provides plants with strong protection from pathogens. however, this response has the potential to be highly deleterious to the host and needs to be tightly controlled. the molecular mechanisms in the plant that regulate the balance between activation and suppression of resistance are not fully understood. previously, we identified arabidopsis suppressor of rps4-rld 1 (srfr1) mutants with enhanced resistance to the bacterial effector avrrps4. these mutants were recess ... | 2009 | 18774967 |
| plant pharming of a full-sized, tumour-targeting antibody using different expression strategies. | the aims of this work were to obtain a human antibody against the tumour-associated antigen tenascin-c (tnc) and to compare the yield and quality of plant-produced antibody in either stable transgenics or using a transient expression system. to this end, the characterization of a full-sized human immunoglobulin g (igg) [monoclonal antibody h10 (mab h10)], derived from a selected single-chain variable fragment (scfv) and produced in plants, is presented. the human mab gene was engineered for plan ... | 2009 | 18793269 |
| a stress-inducible resveratrol o-methyltransferase involved in the biosynthesis of pterostilbene in grapevine. | stilbenes are considered the most important phytoalexin group in grapevine (vitis vinifera) and they are known to contribute to the protection against various pathogens. the main stilbenes in grapevine are resveratrol and its derivatives and, among these, pterostilbene has recently attracted much attention due both to its antifungal and pharmacological properties. indeed, pterostilbene is 5 to 10 times more fungitoxic than resveratrol in vitro and recent studies have shown that pterostilbene exh ... | 2008 | 18799660 |
| a temperature-controlled amplicon system derived from plum pox potyvirus. | the control of replication can facilitate a viral amplicon to reach high expression levels by enabling the virus to escape host defence mechanisms and reducing the deleterious effects of viral infection. we have developed a novel system to regulate amplicon expression by controlling the temperature of plant growth. nicotiana benthamiana plants were transformed at two different temperatures with a cdna copy of the plum pox potyvirus genome harbouring the open reading frame 2 of porcine circovirus ... | 2009 | 18801011 |
| development of a new cucumber mosaic virus-based plant expression vector with truncated 3a movement protein. | we have developed a cucumber mosaic virus (cmv)-based expression vector for the production of heterologous proteins in plants. cell-to-cell movement of cmv is dependent on the presence of coat protein (cp). previous studies have shown that deletion of 33 amino acids (aa) from the carboxy-terminus of the 3a movement protein facilitates cell-to-cell movement that is independent of cp. the cmv-based expression vector that we have designed utilizes this truncated 3a protein, allowing the expression ... | 2008 | 18804833 |
| identification of a movement protein of the tenuivirus rice stripe virus. | rice stripe virus (rsv) is the type member of the genus tenuivirus. rsv has four single-stranded rnas and causes severe disease in rice fields in different parts of china. to date, no reports have described how rsv spreads within host plants or the viral and/or host factor(s) required for tenuivirus movement. we investigated functions of six rsv-encoded proteins using trans-complementation experiments and biolistic bombardment. we demonstrate that nsvc4, encoded by rsv rna4, supports the interce ... | 2008 | 18818319 |
| post-transcriptional gene silencing and virus resistance in nicotiana benthamiana expressing a grapevine virus a minireplicon. | grapevine virus a (gva) is closely associated with the economically important rugose-wood disease of grapevine. in an attempt to develop gva resistance, we made a gfp-tagged gva-minireplicon and utilized it as a tool to consistently activate rna silencing. launching the gva-minireplicon by agroinfiltration delivery resulted in a strong rna silencing response. in light of this finding, we produced transgenic nicotiana benthamiana plants expressing the gva-minireplicon, which displayed phenotypes ... | 2009 | 18821075 |
| molecular divergence of grapevine virus a (gva) variants associated with shiraz disease in south africa. | shiraz disease (sd) is a highly destructive, insect-transmitted disease of noble grapevine cultivars, such as shiraz and merlot, in south africa. earlier studies revealed that, of the three molecular groups of gva that were detected in local vineyards, variants of group ii are closely associated with expression of this disease, and variants of group iii are commonly present in gva-infected sd-negative plants [goszczynski, d.e., 2007. single-strand conformation polymorphism (sscp), cloning and se ... | 2008 | 18822325 |
| the flagellar sigma factor flia is required for dickeya dadantii virulence. | the genome sequence of the enterobacteriaceae phytopathogen dickeya dadantii (formerly erwinia chrysanthemi) revealed homologs of genes required for a complete flagellar secretion system and one flagellin gene. we found that d. dadantii was able to swim and swarm but that ability to swarm was dependent upon both growth media and temperature. mutation of the d. dadantii flia gene was pleiotropic, with the alternate sigma factor required for flagella production and development of disease symptoms ... | 2008 | 18842093 |
| transcriptomic and reverse genetic analyses of branched-chain fatty acid and acyl sugar production in solanum pennellii and nicotiana benthamiana. | acyl sugars containing branched-chain fatty acids (bcfas) are exuded by glandular trichomes of many species in solanaceae, having an important defensive role against insects. from isotope-feeding studies, two modes of bcfa elongation have been proposed: (1) fatty acid synthase-mediated two-carbon elongation in the high acyl sugar-producing tomato species solanum pennellii and datura metel; and (2) alpha-keto acid elongation-mediated one-carbon increments in several tobacco (nicotiana) species an ... | 2008 | 18931142 |
| genome structure and production of biologically active in vitro transcripts of cucurbit-infecting zucchini green mottle mosaic virus. | abstract the complete nucleotide sequence of the zucchini green mottle mosaic virus (zgmmv), a new member of the genus tobamovirus, has been determined. the genome of zgmmv is 6,513 nucleotides long and contains four open reading frames coding for proteins of 131, 189, 28, and 17 kda from the 5' to 3' end, respectively. the 5'- and 3'-non-translated regions consist of 59 and 163 residues, respectively. the sequences of the viral proteins exhibit high identity to the proteins of the members of th ... | 2002 | 18943088 |
| ageratum yellow vein china virus is a distinct begomovirus species associated with a dnabeta molecule. | abstract ageratum conyzoides plants exhibiting yellow vein symptoms, collected near haikou, hainan province, china, contained begomoviral dna-a-like molecules. the complete sequences of the molecules from two samples, hn2 and hn2-19, were shown to consist of 2,768 and 2,748 nucelotides (nt), respectively. these sequences have more than 97% nucleotide sequence identity, but less than 86% identity with other reported begomovirus sequences. in line with the taxonomic convention for begomoviruses, h ... | 2007 | 18943280 |
| pepper (capsicum annuum) is a dead-end host for tomato yellow leaf curl virus. | abstract tomato yellow leaf curl (tylc) is one of the most devastating pathogens affecting tomato (lycopersicon esculentum) worldwide. the disease is caused by a complex of begomovirus species, two of which, tomato yellow leaf curl sardinia virus (tylcsv) and tomato yellow leaf curl virus (tylcv), are responsible for epidemics in southern spain. tylcv also has been reported to cause severe damage to common bean (phaseolus vulgaris) crops. pepper (capsicum annuum) plants collected from commercial ... | 2005 | 18943307 |
| molecular and biological characterization of tomato chlorotic mottle virus suggests that recombination underlies the evolution and diversity of brazilian tomato begomoviruses. | abstract tomato chlorotic mottle virus (tocmov) is an emerging begomovirus species widely distributed throughout tomato-growing regions of brazil. tocmov appears to have expanded its geographic range recently, invading tomato-growing areas that were free of begomovirus infection before 2004. we have determined the first complete genome sequence of an infectious tocmov genome (isolate ba-se1), which is the first begomovirus species isolated in the northeast of brazil. when introduced by particle ... | 2007 | 18943601 |
| tomato leaf curl gujarat virus, a new begomovirus species causing a severe leaf curl disease of tomato in varanasi, india. | abstract the biological and molecular properties of tomato leaf curl gujarat virus from varanasi, india (tolcgv-[var]) were characterized. tolcgv-[var] could be transmitted by grafting and through whitefly transmission in a persistent manner. the full-length genome of dna-a and dna-b of tolcgv-[var] was cloned in puc18. sequence analysis revealed that dna-a (ay190290) is 2,757 bp and dna-b (ay190291) is 2,688 bp in length. tolcgv-[var] could infect and cause symptoms in tomato, pepper, nicotiana ... | 2003 | 18943612 |
| analysis of the spatial distribution of identical and two distinct virus populations differently labeled with cyan and yellow fluorescent proteins in coinfected plants. | abstract apple latent spherical virus (alsv) expressing yellow and cyan fluorescent proteins (alsv-yfp and alsv-cfp) was used to investigate the distribution of identical virus populations in coinfected plants. in chenopodium quinoa plants inoculated with a mixture of alsv-yfp and alsv-cfp, fluorescence from yfp and cfp was always distributed separately in both inoculated and upper uninoculated leaves. inoculation of each alsv-yfp and alsv-cfp to different leaves of a c. quinoa plant resulted in ... | 2007 | 18943677 |
| characterization of a u.s. isolate of beet black scorch virus. | abstract the first reported u.s. isolate of beet black scorch necrovirus (bbsv) was obtained and characterized. host range of the virus for localized and occasionally systemic infection included the chenopodiaceae and tetragonia expansa; nicotiana benthamiana supported symptomless systemic infection by the virus. the complete nucleotide sequence of the genomic rna of the virus, designated bbsv-co, exhibits 93% similarity to the genome of the 'ningxia' isolate of bbsv from china. amino acid seque ... | 2007 | 18943682 |
| chimeric cdna sequences from citrus tristeza virus confer rna silencing-mediated resistance in transgenic nicotiana benthamiana plants. | abstract rna silencing has been shown to be an important mechanism for conferring resistance in transgenic, virus-resistant plants. we used this approach to evaluate resistance in nicotiana benthamiana plants transformed with chimeric coding and noncoding sequences from citrus tristeza virus (ctv). several independent transgenic plant lines were generated, using two constructs (pctv1 and pctv2) designed to produce self-complementary transcripts. the pctv1 contained cdna sequences from the ctv ca ... | 2006 | 18943746 |
| a novel mite-transmitted virus with a divided rna genome closely associated with pigeonpea sterility mosaic disease. | abstract the agent of sterility mosaic, a disease that is a major constraint on pigeonpea (cajanus cajan) production in the indian subcontinent, is transmitted by the eriophyid mite, aceria cajani. this agent has remained elusive for decades despite intensive efforts but we report the isolation of highly flexuous filamentous virus-like particles (vlps) of 3 to 10 nm in width and of undefined lengths from sterility mosaic disease (smd)-affected pigeonpea plants. purified vlp preparations from vir ... | 2003 | 18944159 |
| tomato leaf curl karnataka virus from bangalore, india, appears to be a recombinant begomovirus. | abstract the genome of tomato leaf curl virus (tolcv) from bangalore, india, a whitefly-transmitted geminivirus, was cloned (pind9) and sequenced. the circular dna of 2,759 nucleotides (u38239) is organized similarly to that of other begomoviruses with monopartite genomes. comparison of the nucleotide sequence of pind9 with other tomato-associated begomoviruses from india (tomato leaf curl bangalore virus [tolcbv, z48182]) and tomato leaf curl new delhi virus-severe (tolcndv-svr, u15015) showed ... | 2002 | 18944261 |
| interactions between geminiviruses in a naturally occurring mixture: pepper huasteco virus and pepper golden mosaic virus. | abstract pepper huasteco virus (phv) and pepper golden mosaic virus (pepgmv) are found in mixtures in many horticultural crops in mexico. this combination constitutes an interesting, naturally occurring model system to study several aspects of virus-virus interactions. possible interactions between phv and pepgmv were studied at four levels: symptom expression, gene expression, replication, and movement. in terms of symptom expression, the interaction was shown to be host-dependent because antag ... | 2003 | 18944336 |
| a single amino acid mutation in the plum pox virus helper component-proteinase gene abolishes both synergistic and rna silencing suppression activities. | abstract the effects on symptom expression of single amino acid mutations in the central region of the plum pox virus (ppv) helper component-proteinase (hc-pro) gene were analyzed in nicotiana benthamiana using potato virus x (pvx) recombinant viruses. pvx recombinant virus expressing the wild-type variant of ppv hc-pro induced the expected enhancement of pvx pathogenicity, manifested as necrosis and plant death. recombinant virus expressing a variant of ppv hc-pro containing a single point muta ... | 2005 | 18944411 |
| tobacco curly shoot virus dnabeta is not necessary for infection but intensifies symptoms in a host-dependent manner. | abstract we demonstrated that only 11 isolates were associated with dnabeta among 39 tobacco curly shoot virus (tbcsv)-infected, field-collected samples. an infectious clone of tbcsv-[y35], an isolate associated with dnabeta, induced severe upward leaf curling in nicotiana benthamiana. in the presence of its cognate dnabeta (tbcsv-[y35] dnabeta), the symptom changed to a downward leaf curl. furthermore, tbcsv-[y35] alone was able to induce severe symptoms in tobacco and tomato plants, although c ... | 2005 | 18944412 |
| the helper component-proteinase of sweet potato feathery mottle virus facilitates systemic spread of potato virus x in ipomoea nil. | abstract when ipomoea nil was coinfected with sweet potato feathery mottle virus (spfmv), a member of the genus potyvirus, and potato virus x (pvx) typical symptoms caused by pvx were observed on those by spfmv on the first upper true leaves at 14 days postinoculation (dpi). on the other hand, no pvx-induced symptoms were observed on the first upper true leaves at 14 dpi when plants were infected with pvx alone. in the case of coinfection with pvx and spfmv, pvx rna was detected not only in the ... | 2000 | 18944517 |
| complementation of coat protein mutants of pepper huasteco geminivirus in transgenic tobacco plants. | abstract the role of the pepper huasteco virus (phv) coat protein (cp) gene during the infection was investigated in three different hosts by using mutations that produced truncated proteins and by complementation assays in transgenic plants. the infectivity analysis revealed that mutants that express truncated cp (cp7 and cp191) behave like the wild-type virus when inoculated onto pepper and nicotiana benthamiana plants in terms of symptom expression and viral dna movement. on the contrary, the ... | 1999 | 18944688 |
| detection of cymbidium mosaic potexvirus and odontoglossum ringspot tobamovirus using immuno-capillary zone electrophoresis. | abstract immuno-capillary zone electrophoresis (i-cze) is a technique that combines the specificity afforded by serological assays with the sensitivity, rapidity, and automation in detection provided by capillary zone electrophoresis. cymbidium mosaic potexvirus (cymmv) and odontoglossum ringspot tobamovirus (orsv) were detected in their purified forms as well as in the crude saps of infected nicotiana benthamiana leaves and oncidium orchid flowers. the two orchid virus-antibody complexes were r ... | 1999 | 18944725 |
| homology-dependent virus resistance in transgenic plants with the coat protein gene of sweet potato feathery mottle potyvirus: target specificity and transgene methylation. | abstract nicotiana benthamiana plants were transformed with the coat protein (cp) coding sequence and the 3' nontranslated region (ntr) of the severe strain of sweet potato feathery mottle potyvirus (spfmv-s). regenerated lines were screened for virus resistance using recombinant potato virus x (pvx) engineered to contain the sequence homologous to the transgene. out of 19 transgenic lines, 7 showed virus resistance after inoculation by the recombinant pvx. in most of the resistant lines, relati ... | 1999 | 18944751 |
| molecular and serological characterization of iris yellow spot virus, a new and distinct tospovirus species. | abstract a new tospovirus was identified in iris cultivations in the netherlands. both serological comparisons and sequence determination of the s rna demonstrate that this virus represents a new and distinct species, belonging to a separate serogroup, and for which the name iris yellow spot virus (iysv) is proposed. the disease symptoms on iris are characterized by yellow spots on the leaves. its experimental host range is very narrow and, in addition to iris, only includes nicotiana benthamian ... | 1998 | 18944829 |
| replication specificity elements of the worland strain of beet curly top virus are compatible with those of the cfh strain but not those of the cal/logan strain. | abstract cloned genomes of the cfh, worland, and cal/logan strains of beet curly top virus (bctv) served as helper viruses to trans-replicate defective (d) dnas that are incapable of self-replication due to deletions within the c1 open reading frame encoding the replication initiator (rep) protein. the logan rep protein could trans-replicate a logan-derived d dna in a transient replication assay conducted in nicotiana benthamiana leaf disks. however, the logan rep protein was unable to trans-rep ... | 1998 | 18944850 |
| defective movement of viruses in the family bromoviridae is differentially complemented in nicotiana benthamiana expressing tobamovirus or dianthovirus movement proteins. | abstract taxonomically distinct tobacco mosaic tobamovirus (tmv), red clover necrotic mosaic dianthovirus (rcnmv), cucumber mosaic cucumovirus (cmv), brome mosaic bromovirus (bmv), and cowpea chlorotic mottle bromovirus (ccmv) exhibit differences in their host range. each of these viruses encodes a functionally similar nonstructural movement protein (mp) that is essential for cell-to-cell movement of a progeny virus. despite the lack of significant amino acid identity among the mps of cmv, tmv, ... | 1998 | 18944938 |
| comparison of ambisense m rna of watermelon silver mottle virus with other tospoviruses. | abstract double-stranded genomic rnas (dsrnas) extracted from chenopodium quinoa infected with watermelon silver mottle virus (wsmv) were similar to those of tomato spotted wilt virus (tswv, serogroup i) and impatiens necrotic spot virus (insv, serogroup iii), except that the s dsrna of wsmv is 0.75 and 0.6 kbp longer than those of tswv and insv, respectively. the complete nucleotide sequence of the genomic m rna of wsmv was determined from cdna clones generated from separated m dsrna. the m rna ... | 1998 | 18944959 |
| effects of temperature and host on the generation of tomato spotted wilt virus defective interfering rnas. | abstract the generation of defective interfering (di) rna molecules of tomato spotted wilt tospovirus (tswv) was studied by serially passaging in-ocula from plant to plant under different controlled conditions. di rnas were generated at higher rates in plants at 16 degrees c than in plants incubated at higher temperatures. another factor promoting the tswv di rna generation was the use of high virus concentrations in the inocula. the solanaceous species capsicum annuum, datura stramonium, lycope ... | 1997 | 18945014 |
| serological detection of grapevine virus a using antiserum to a nonstructural protein, the putative movement protein. | abstract grapevine virus a (gva) is implicated in the etiology of the rugose wood disease. the coat protein (cp) and the putative movement protein (mp) genes of gva were cloned and expressed in escherichia coli and used to produce antisera. both the cp and the mp were detected with their corresponding antisera in gva-infected nicotiana benthamiana. the mp was first detected at an early stage of the infection, 6 to 12 h after inoculation, and the cp was detected 2 to 3 days after inoculation. the ... | 1997 | 18945038 |
| inhibition of long-distance movement of rna silencing signals in nicotiana benthamiana by apple chlorotic leaf spot virus 50 kda movement protein. | apple chlorotic leaf spot virus 50 kda movement protein (p50) acts as a suppressor of systemic silencing in nicotiana benthamiana. here, we investigate the mode of action of p50 suppressor. an agroinfiltration assay in gfp-expressing n. benthamiana line16c (gfp-plant) showed that p50 could not prevent the short-distance spread of silencing. in grafting experiments, the systemic silencing was inhibited in gfp-plants (scion) grafted on p50-expressing n. benthamiana (p50-plant; rootstock) when gfp ... | 2008 | 18954886 |
| lebzip2 induced by salt and drought stress and transient overexpression by agrobacterium. | the full-length cdna of lebzip2 (lycopersicon esculentum bzip2) encodes a protein of 164 amino acids and contains a n-terminal basic-region leucine zipper domain. analysis of the deduced tomato lebzip2 amino acid sequence revealed that it shares 85% sequence identity with both tobacco bzip and pepper ccbzip. lebzip2 mrna is expressed at a high level exclusively in flowers. presently, lebzip2 was strongly increased also following nacl and mannitol treatments. no significant lebzip2 expression was ... | 2008 | 18959814 |
| replication and encapsidation of recombinant turnip yellow mosaic virus rna. | turnip yellow mosaic virus (tymv) is a positive strand rna virus that infects mainly cruciferae plants. in this study, the tymv genome was modified by inserting an extra subgenomic rna promoter and a multiple cloning site. this modified tymv was introduced into nicotiana benthamiana using a agrobacterium-mediated t-dna transfer system (agroinfiltration). when a gene encoding beta-glucuronidase or green fluorescent protein was expressed using this modified tymv as a vector, replication of the rec ... | 2008 | 18959822 |
| highly efficient expression of escherichia coli heat-labile enterotoxin b subunit in plants using potato virus x-based vector. | a synthetic gene of the b-subunit of escherichia coli heat-labile toxin, optimized for expression in plants, was designed and synthesized. the recombinant viral vector was constructed on the basis of potato virus x containing the ltb gene instead of the removed triple block of transport genes and the coat protein gene, which provides for ltb expression in plants. the vector is introduced into the plant cells during cell infiltration by agrobacteria incorporating a binary vector, the t-dna region ... | 2008 | 18991556 |
| evaluation of two gene-silencing constructs for resistance to tomato yellow leaf curl viruses in nicotiana benthamiana plants. | infiltration of agrobacterium tumefaciens into intact plant leaves of n. benthamiana was used to test the efficiency of two virus-based silencing constructs conferring resistance to the closely related begomoviruses. the constructs contained the most conserved sequences of the coat protein (cp) gene and replication-associated protein (rep) gene of tomato yellow leaf curl sardinia virus (sicily strain) (tylcsv-[sic]). both constructs formed a hairpin structure that enhanced the post-transcription ... | 2008 | 18999888 |
| co-infection by two criniviruses alters accumulation of each virus in a host-specific manner and influences efficiency of virus transmission. | tomato chlorosis virus (tocv), and tomato infectious chlorosis virus (ticv), family closteroviridae, genus crinivirus, cause interveinal chlorosis, leaf brittleness, and limited necrotic flecking or bronzing on tomato leaves. both viruses cause a decline in plant vigor and reduce fruit yield, and are emerging as serious production problems for field and greenhouse tomato growers in many parts of the world. the viruses have been found together in tomato, indicating that infection by one criniviru ... | 2008 | 19000010 |
| tandem leader proteases of grapevine leafroll-associated virus-2: host-specific functions in the infection cycle. | several viruses in the genus closterovirus including grapevine leafroll-associated virus-2 (glrav-2), encode a tandem of papain-like leader proteases (l1 and l2) whose functional profiles remained largely uncharacterized. we generated a series of the full-length, reporter-tagged, clones of glrav-2 and demonstrated that they are systemically infectious upon agroinfection of an experimental host plant nicotiana benthamiana. these clones and corresponding minireplicon derivatives were used to addre ... | 2009 | 19007962 |
| replication promiscuity of dna-beta satellites associated with monopartite begomoviruses; deletion mutagenesis of the ageratum yellow vein virus dna-beta satellite localizes sequences involved in replication. | pseudorecombination studies in nicotiana benthamiana demonstrate that ageratum yellow vein virus (ayvv) and eupatorium yellow vein virus (epyvv) can functionally interact with dna-beta satellites associated with ayvv, epyvv, cotton leaf curl multan virus (clcumv) and honeysuckle yellow vein virus (hyvv). in contrast, clcumv shows some specificity in its ability to interact with distinct satellites and hyvv is able to interact only with its own satellite. using an n. benthamiana leaf disk assay, ... | 2008 | 19008407 |
| grapevine virusa-mediated gene silencing in nicotiana benthamiana and vitis vinifera. | virus-induced gene silencing (vigs) is an attractive approach for studying gene function. although the number of virus vectors available for use in vigs experiments has increased in recent years, most of these vectors are applied in annual or herbaceous plants. the aim of this work was to develop a vigs vector based on the grapevine virus a (gva), which is a member of the genus vitivirus, family flexiviridae. the gva vector was used to silence the endogenous phytoene desaturase (pds) gene in nic ... | 2009 | 19010356 |
| strains of a new bipartite begomovirus, pepper yellow leaf curl indonesia virus, in leaf-curl-diseased tomato and yellow-vein-diseased ageratum in indonesia. | the complete nucleotide sequences of begomoviruses from pepper with leaf curl and yellowing symptoms, tomato with leaf curl symptoms, and ageratum with yellow vein in indonesia were determined. on the basis of genome organization and sequence homology, they were proposed to belong to a new species, pepper yellow leaf curl indonesia virus (pepylciv), which includes the new strains pepylciv-tomato and pepylciv-ageratum. these viruses had bipartite genomes. pepper virus dnas from indonesia (pepylci ... | 2008 | 19015934 |
| wtse, an avre-family type iii effector protein of pantoea stewartii subsp. stewartii, causes cell death in non-host plants. | pantoea stewartii subsp. stewartii (pnss) causes stewart's bacterial wilt of sweet corn and leaf blight of maize. the pathogenicity of pnss depends on synthesis of extracellular polysaccharide and an hrp type iii secretion system. wtse, a type iii secreted effector protein, is essential for the virulence of pnss on corn. it belongs to the avre family of effectors, which includes dspa/e from erwinia amylovora and avre1 from pseudomonas syringae. previously, wtse was shown to cause disease-associa ... | 2008 | 19018993 |
| influence of cytoplasmic heat shock protein 70 on viral infection of nicotiana benthamiana. | the accumulation of heat shock protein 70 (hsp70) generally occurs in plants infected with viruses. however, the effect of hsp70 accumulation on plant viral infection and pathogenesis remains elusive. in this study, the expression of six hsp70 genes was found to be induced by the four diverse rna viruses, tobacco mosaic virus, potato virus x (pvx), cucumber mosaic virus and watermelon mosaic virus, in nicotiana benthamiana. heat treatment enhanced the accumulation and systemic infection of these ... | 2008 | 19019009 |
| evidence for alternate states of cucumber mosaic virus replicase assembly in positive- and negative-strand rna synthesis. | cucumber mosaic virus (cmv) encodes two viral replication proteins, 1a and 2a. accumulating evidence implies that different aspects of 1a-2a interaction in replication complex assembly are involved in the regulation of virus replication. to further investigate cmv replicase assembly and to dissect the involvement of replicase activities in negative- and positive-strand synthesis, we transiently expressed cmv rnas and/or proteins in nicotiana benthamiana leaves using a dna or rna-mediated express ... | 2009 | 19022467 |
| identification of miniature inverted-repeat transposable elements (mites) and biogenesis of their sirnas in the solanaceae: new functional implications for mites. | small rnas regulate the genome by guiding transcriptional and post-transcriptional silencing machinery to specific target sequences, including genes and transposable elements (tes). although miniature inverted-repeat transposable elements (mites) are closely associated with euchromatic genes, the broader functional impact of these short te insertions in genes is largely unknown. we identified 22 families of mites in the solanaceae (mis1-mis22) and found abundant mis insertions in solanaceae geno ... | 2009 | 19037014 |
| inhibitors of plant invertases do not affect the structurally related enzymes of fructan metabolism. | plant fructan active enzymes (fazys), including the enzymes involved in inulin metabolism, namely sucrose:sucrose 1-fructosyltransferase (1-sst; ec 2.4.1.99), fructan:fructan 1-fructosyltransferase (1-fft; ec 2.4.1.100) and fructan 1-exohydrolase (1-feh; ec 3.2.1.153), are evolutionarily related to acid invertases (ais), that is, plant cell wall invertase (cwi) and vacuolar invertase (vi). acid invertases are post-translationally controlled by proteinaceous inhibitors. whether fazys are subject ... | 2009 | 19037899 |
| biochemical and immunological characterization of the plant-derived candidate human immunodeficiency virus type 1 mucosal vaccine ctb-mpr. | plants are potentially the most economical platforms for the large-scale production of recombinant proteins. thus, plant-based expression of subunit human immunodeficiency virus type 1 (hiv-1) vaccines provides an opportunity for their global use against the acquired immunodeficiency syndrome pandemic. ctb-mpr(649-684)[ctb, cholera toxin b subunit; mpr, membrane proximal (ectodomain) region of gp41] is an hiv-1 vaccine candidate that has been shown previously to induce antibodies that block a pa ... | 2009 | 19037902 |
| the p0 gene of sugarcane yellow leaf virus encodes an rna silencing suppressor with unique activities. | the sugarcane yellow leaf virus (scylv) p0, a member of the highly heterologous proteins of poleroviruses, is a suppressor of posttranscriptional gene silencing (ptgs) and has additional activities not seen in other p0 proteins. the p0 protein in previously tested poleroviruses (beet western yellows virus and cucurbit aphid-borne yellows virus), suppresses local, but not systemic, ptgs induced by both sense gfp and inverted repeat gf using its f-box-like domain to mediate destabilization of the ... | 2009 | 19046592 |
| diverse and newly recognized effects associated with short interfering rna binding site modifications on the tomato bushy stunt virus p19 silencing suppressor. | the tomato bushy stunt virus-encoded p19 forms dimers that bind duplex short interfering rnas (sirnas) to suppress rna silencing. p19 is also involved in multiple host-specific activities, including the elicitation of symptoms, and in local and/or systemic spread. to study the correlation between those various roles and the sirna binding by p19, predicted sirna-interacting sites were modified. twenty-two mutants were generated and inoculated onto nicotiana benthamiana plants, to reveal that (i) ... | 2009 | 19052093 |
| the pseudomonas syringae effector protein, avrrps4, requires in planta processing and the krvy domain to function. | a pseudomonas syringae pv. pisi effector protein, avrrps4, triggers rps4-dependent immunity in arabidopsis. we characterized biochemical and genetic aspects of avrrps4 function. secretion of avrrps4 from pst dc3000 is type iii secretion-dependent, and avrrps4 is processed into a smaller form in plant cells but not in bacteria or yeast. agrobacterium-mediated transient expression analysis of n-terminally truncated avrrps4 mutants revealed that the c-terminal 88 amino acids are sufficient to trigg ... | 2009 | 19054367 |
| curtovirus-cucurbit interaction: acquisition host plays a role in leafhopper transmission in a host-dependent manner. | curly top disease (ctd) of vegetable crops is caused by viruses in the genus curtovirus (family geminiviridae). cucurbits are reported to be susceptible to ctd; however, the disease is rare in california despite annual outbreaks in other hosts (e.g., common bean, pepper, sugar beet, and tomato). consistent with these observations, no obvious curly top symptoms were observed in melon fields surveyed for ctd in central california in 2004 and 2005, whereas the disease was readily observed in tomato ... | 2009 | 19055441 |
| a critical domain of the cucumber mosaic virus 2b protein for rna silencing suppressor activity. | alignment of cucumber mosaic virus (cmv) 2b protein sequences from two cmv subgroups revealed two highly variable regions. to examine contributions of variable sequence domains to the suppressor activity, we performed a comparative study between 2b proteins of a subgroup i strain (sd-cmv) and a subgroup ii strain (q-cmv). here we show that the suppressor activity of sd2b is stronger than that of q2b and that a domain existent in sd2b but absent in q2b is a major determinant of the suppressor act ... | 2009 | 19059248 |
| production of cucumber mosaic virus rna5 and its role in recombination. | cucumber mosaic virus (cmv) is a plant infecting tripartite positive-strand rna virus. in addition to three genomic and two known subgenomic rnas, cmv strains of subgroup ii (e.g. q-cmv), but not subgroup i (e.g. fny-cmv), produce and package a redundant rna5 encompassing the 3' 304-307 nucleotides of rnas 2 and 3. the mechanism regulating rna5 production and its role in cmv life cycle is unknown. in this study, transient expression of q2 or q3 by agroinfiltration into nicotiana benthamiana plan ... | 2009 | 19059620 |
| ay-wb phytoplasma secretes a protein that targets plant cell nuclei. | the fully sequenced genome of aster yellows phytoplasma strain witches' broom (ay-wb; candidatus phytoplasma asteris) was mined for the presence of genes encoding secreted proteins based on the presence of n-terminal signal peptides (sp). we identified 56 secreted ay-wb proteins (sap). these sap are candidate effector proteins potentially involved in interaction with plant and insect cell components. one of these sap, sap11, contains an n-terminal sp sequence and a eukaryotic bipartite nuclear l ... | 2009 | 19061399 |
| serine palmitoyltransferase, the first step enzyme in sphingolipid biosynthesis, is involved in nonhost resistance. | an overexpression screen of nicotiana benthamiana cdnas identified a gene for the lcb2 subunit of serine palmitoyltransferase (spt) as a potent inducer of hypersensitive response-like cell death. the pyridoxal 5'-phosphate binding site of nblcb2 is required for its function as a cell death inducer. nblcb2 mrna is accumulated after infection by nonhost pathogen pseudomonas cichorii. resistance of n. benthamiana against p. cichorii was compromised by treatment with an spt inhibitor and in nblcb2- ... | 2009 | 19061400 |
| influenza virus-like particles produced by transient expression in nicotiana benthamiana induce a protective immune response against a lethal viral challenge in mice. | a strain-specific vaccine represents the best possible response to the threat of an influenza pandemic. rapid delivery of such a vaccine to the world's population before the peak of the first infection wave seems to be an unattainable goal with the current influenza vaccine manufacturing capacity. plant-based transient expression is one of the few production systems that can meet the anticipated surge requirement. to assess the capability of plant agroinfiltration to produce an influenza vaccine ... | 2008 | 19076615 |
| the lcb2 subunit of the sphingolip biosynthesis enzyme serine palmitoyltransferase can function as an attenuator of the hypersensitive response and bax-induced cell death. | previous results showed that expression of the gene encoding the long-chain base2 (lcb(2)) subunit of serine palmitoyltransferase (spt), designated bclcb(2), from nonheading chinese cabbage (brassica campestris ssp. chinensis) was up-regulated during hypersensitive cell death (hcd) induced by the phytophthora boehmeriae elicitor pb90. overexpression of bclcb(2) in nicotiana tabacum leaves suppressed the hcd normally initiated by elicitors and pb90-triggered h(2)o(2) accumulation. bclcb(2) also f ... | 2009 | 19076721 |
| investigating recombinant protein exudation from roots of transgenic tobacco. | it is widely acknowledged that plant-made pharmaceuticals (pmps) offer numerous benefits, including inexpensive production, biological safety and the facility for production at agricultural scale. at the same time, it is important to minimize any potential risk associated with this new technology, including the potential release of bioactive proteins into the environment. to address this issue, we studied transgenic nicotiana benthamiana and nicotiana tabacum plants expressing two recombinant si ... | 2008 | 19081009 |
| leaf proteome analysis of transgenic plants expressing antiviral antibodies. | the expression of exogenous antibodies in plant is an effective strategy to confer protection against viral infection or to produce molecules with pharmaceutical interest. however, the acceptance of the transgenic technology to obtain self-protecting plants depends on the assessment of their substantial equivalence compared to non-modified crops with an established history of safe use. in fact, the possibility exists that the introduction of transgenes in plants may alter expression of endogenou ... | 2009 | 19099506 |
| hairy-root organ cultures for the production of human acetylcholinesterase. | human cholinesterases can be used as a bioscavenger of organophosphate toxins used as pesticides and chemical warfare nerve agents. the practicality of this approach depends on the availability of the human enzymes, but because of inherent supply and regulatory constraints, a suitable production system is yet to be identified. | 2008 | 19105816 |
| characterization of a member of a new potyvirus species infecting arracacha in brazil. | an arracacha (arracacia xanthorrhiza) plant collected in brazil was found to be infected by a new virus. this viral isolate (named c17) systemically infected nicotiana benthamiana and apium graveolens. a polyclonal antibody was raised, and analysis of our arracacha germplasm collection showed a high infection rate of c17-like viruses (93% infection). sequencing of the ca. 1.7 kb 3'-terminal genomic region revealed a typical potyvirus genome organization. it shared less than 70% nucleotide identi ... | 2009 | 19109690 |
| functional characterization of a stilbene synthase gene using a transient expression system in planta. | the expression and functionality of a resveratrol synthase (rs) gene from peanut (arachis hypogaea) was studied using an agrobacterium tumefaciens-mediated transient expression system in nicotiana benthamiana leaves. functional analysis of rs was demonstrated by tracking its expression during 96 h. to measure the transcripts levels of rs transgene, real-time qrt-pcr was used and revealed that the highest level of transcripts was at 48 h post-transfection. western blot analyses showed that rs pro ... | 2009 | 19116720 |
| forca, a promoter element that responds to crosstalk between defense and light signaling. | recognition of pathogenic microorganisms triggers in plants comprehensive transcriptional reprogramming. in order to identify transcriptome-level control elements required for plant immune responses we are examining several sets of genes found by microarray experiments to be co-activated in arabidopsis thaliana (arabidopsis) seedlings infected with the oomycete hyaloperonospora parasitica. promoter motifs conserved in clusters of co-expressed genes may be involved in mediating coordinated gene a ... | 2009 | 19128484 |
| compromised virus-induced gene silencing in rdr6-deficient plants. | rna silencing in plants serves as a potent antiviral defense mechanism through the action of small interfering rnas (sirnas), which direct rna degradation. sirnas can be derived directly from the viral genome or via the action of host-encoded rna-dependent rna polymerases (rdrs). plant genomes encode multiple rdrs, and it has been demonstrated that plants defective for rdr6 hyperaccumulate several classes of virus. in this study, we compared the effectiveness of virus-induced gene silencing (vig ... | 2009 | 19129420 |
| allelic variants of the pseudomonas syringae type iii effector hopz1 are differentially recognized by plant resistance systems. | the bacterial plant pathogen pseudomonas syringae depends on the type iii secretion system and type iii-secreted effectors to cause disease in plants. hopz is a diverse family of type iii effectors widely distributed in p. syringae isolates. among the hopz homologs, hopz1 is ancient to p. syringae and has been shown to be under strong positive selection driven by plant resistance-imposed selective pressure. here, we characterized the virulence and avirulence functions of the three hopz1 alleles ... | 2009 | 19132870 |
| subcellular localization and expression of bamboo mosaic virus satellite rna-encoded protein. | the satellite rna of bamboo mosaic virus (satbamv) has a single open reading frame encoding a non-structural protein, p20, which facilitates long-distance movement of satbamv in bamv and satbamv co-infected plants. immunohistochemistry and immunoelectron microscopy revealed that the p20 protein accumulated in the cytoplasm and nuclei in co-infected cells. p20 and the helper virus coat protein (cp) were highly similar in their subcellular localization, except that aggregates of bamv virions were ... | 2009 | 19141462 |
| transient protein expression in three pisum sativum (green pea) varieties. | the expression of proteins in plants both transiently and via permanently transformed lines has been demonstrated by a number of groups. transient plant expression systems, due to high expression levels and speed of production, show greater promise for the manufacturing of biopharmaceuticals when compared to permanent transformants. expression vectors based on a tobacco mosaic virus (tmv) are the most commonly utilized and the primary plant used, nicotiana benthamiana, has demonstrated the abili ... | 2009 | 19156736 |
| grapevine fanleaf virus (gflv)-specific antibodies confer gflv and arabis mosaic virus (armv) resistance in nicotiana benthamiana. | grapevine fanleaf virus (gflv) is one of the most destructive pathogens of grapevine. in this study, we generated monoclonal antibodies binding specifically to the coat protein of gflv. antibody fl(3), which bound most strongly to gflv and showed cross-reactivity to arabis mosaic virus (armv), was used to construct the single-chain antibody fragment scfvgflvcp-55. to evaluate the potential of this single-chain variable fragment (scfv) to confer antibody-mediated virus resistance, transgenic nico ... | 2009 | 19161351 |
| chimeras between oilseed rape mosaic virus and tobacco mosaic virus highlight the relevant role of the tobamoviral rdrp as pathogenicity determinant in several hosts. | oilseed rape mosaic virus (ormv) is a tobamovirus taxonomically distinct from the type member of the genus, tobacco mosaic virus (tmv). both viruses display a specific host range, although they share certain hosts, such as arabidopsis thaliana, nicotiana benthamiana and n. tabacum, on which they induce different symptoms. using a gain-of-symptom approach, we generated chimeric viruses, starting from a tmv infectious clone, over which different regions of ormv were exchanged with their correspond ... | 2009 | 19161353 |
| tomato yellow leaf curl thailand virus-[y72] from yunnan is a monopartite begomovirus associated with dnabeta. | previous studies have shown that isolates of tomato yellow leaf curl thailand virus (tylcthv) originated from thailand are bipartite begomoviruses, while all the seven tylcthv isolates found in china are associated with dnabeta molecules. in this study, infectious clones of tylcthv isolate y72 (tylcthv-[y72]) and its dnabeta were constructed to verify the bipartite or monopartite nature of tylcthv. agroinoculation showed that tylcthv-[y72] alone was able to induce significant symptoms in nicotia ... | 2009 | 19165588 |
| efficient virus-induced gene silencing in plants using a modified geminivirus dna1 component. | virus-induced gene silencing (vigs) is currently recognized as a powerful reverse genetics tool for application in functional genomics. dna1, a satellite-like and single-stranded dna molecule associated with begomoviruses (family geminiviridae), has been shown to replicate autonomously but requires the helper virus for its dissemination. we developed a vigs vector based on the dna1 component of tobacco curly shoot virus (tbcsv), a monopartite begomovirus, by inserting a multiple cloning site bet ... | 2009 | 19175519 |
| rapid system for evaluating bioproduction capacity of complex pharmaceutical proteins in plants. | transgene product yield remains a key limitation in commercializing plant-derived pharmaceutical proteins. although significant progress has been made in understanding the roles of promoters, enhancers, integration sites, codon usage, cryptic rna sites, silencing, and product compartmentalization on product yield and quality, researchers still cannot reliably predict which proteins will be produced at high levels or what manipulations will guarantee enhanced productivity. we have optimized a sim ... | 2009 | 19183893 |
| expressing a whitefly groel protein in nicotiana benthamiana plants confers tolerance to tomato yellow leaf curl virus and cucumber mosaic virus, but not to grapevine virus a or tobacco mosaic virus. | transgenesis offers many ways to obtain virus-resistant plants. however, in most cases resistance is against a single virus or viral strain. we have taken a novel approach based on the ability of a whitefly endosymbiotic groel to bind viruses belonging to several genera, in vivo and in vitro. we have expressed the groel gene in nicotiana benthamiana plants, postulating that upon virus inoculation, groel will bind to virions, thereby interfering with pathogenesis. the transgenic plants were inocu ... | 2009 | 19184338 |